Carburetor



July 9, 1940.

E. K. CHAFFIN 2,207,533

CARBURETOR Filed Jan. 3, 1940 2 Sheets-Sheet 1 I I H .29 A Z3 20 a! Inum H H law 21 I 4 1' JH ll I Inventor K. CHA FF/N/ A iiomeys ly 1940- E. K. CHAFFIN I CARBURETOR 2 Sheets-Sheet 2 Filed Jan. 5, 1940 Inventor Attorneys Patented July 9, 1940 UNITED STATES PATENT OFFICE 1 Claim.

My invention relates to improvement in carburetors and more particularly to dual carburetors so-called.

The invention is designed with the particular object in view of providing a unitary, dual carburetor of practical, inexpensive construction and a high degree of efficiency adapted for selective use under control of a single simplified valve to supply carbureted fuel either from a common fuel tank or from two separate tanks,

as desired, and whereby carburetor failure particularly in airplane power plants may be obviated. P To the accomplishment of the above, and subordinate objects presently appearing, a preferred embodiment of my invention has been illustrated in the accompanying drawings, set forth in detail in the succeeding description, and defined I in the appended claim. In said drawings:

Figure 1 is a view in side elevation of the preferred embodiment of my invention,

Figure 2 is a view in end elevation,

Figure 3 is a view in vertical longitudinal 25 section, and

Figure 4 is a view in horizontahsection taken on the line 44 of Figure 3 looking downwardly and indicated by the arrows.

Referring to the drawings by numerals, the illustrated embodiment of my invention comprises, as its basic element, a main, substantially tubular, upright section" I having a closed bottom 2 and forming a mixing chamber 3, a pair of cup-like sections 4 at diametrically opposite sides of the section I, respectively, having bottoms 5 preferably dropped below the bottom 2, and forming a pair of float chambers 6, a pair of upper side extensions I on the sides of the sections 4, respectively, in the plane of the said sections I and'4 and forming valve chambers 8 opening into the float chambersfi, a lateral, main air inlet conduit 9 at the bottom of the main section I, intermediate the sections 4,. and a pair of cover plates I0 detachably secured by screws II 45 to the tops of the sections 4.

The main section I is provided in the top thereof with the usual type of buterfly throttle valve I2. The bottom 2 of the main section I is provided with a diametrical bore l3 therein 50 opening into the bottoms of both float chambers 6 and forming, as will presently more clearly appear, a valve casing. A pair of fuel discharge ports I4 are provided in the bottom 2 of section I at diametrically opposite sides thereof, and adjacent to the float chambers Ii, respectively, in

- the line of the bore I3 and leading upwardly from said bore. A pair of nozzle-type, main inlet jets I are threaded at the lower ends thereof into the ports I4, respectively, to extend therefrom up into the mixing chamber 3, said jets converging toward the axis of said chamberinto close proximity at the 'upper ends thereof. A sleeve I6 of hour-glass form fitted into the section I and secured therein between the conduit 9 and valve I2 provides a restricted throat above said jets l5 and conduit 9 for facilitating mixing the spray from the nozzles I5 with the air in the mixing chamber 3. One of the discharge ports I4 and the main jet I5 thereof are related to each of the float chambers 6 for a purpose presently apparent.

Idling jets are provided in the form of a pair of ducts I! in the wall of the section I extending downwardly side by side in a vertical boss on said section from the top of said boss and 20' through the bottom 2 of the section I into the ports I4, respectively, beneath the jets I5, said jets, or .ducts I'I being suitably arranged at the upper ends thereof for the entrance of air thereinto. A single air adjustment I9 controls air 26 mixture for idling, regardless of which idling jet is furnishing fuel.

A pair of gasoline feed lines 20 are connected to the bottoms of the needle valve chambers .8 by couplings 2| and nipples 22, said nipples open- 80 ing into vertical inlet ports 23 provided in the bottoms of said chambers. A pair of needle valve seats 24 are threaded downwardly into the bottoms of the needle valve chambers 8 in registration with, the ports 23, respectively. A pair of suitable floats 25 in the float chambers 6, respectively, are pivotally mounted therein, as at- 26, and operatively connected as' at 21 to vertically slidableneedle valves 28 in said chambers 8, said valves coacting with the seats 24 in the usual manner and under control of the floats 25 to control the level of the gasoline in their related float chambers '6. Feed lines 20 may be connected to the main supply tank of the power plant, or, one to said tank and the other to an auxiliary tank, neither tank being shown.

A rotary tubular valve 29 is extended through a suitable bearing boss 3!] provided on the sections 4, and through the float chamber 6 of said section and the bore I3 into the other float chamber 6, said valve having an outer end extending out of said boss 30 and equipped with a crank 31 to which a suitable operating rod 32 is pivoted. A set screw 33 extended through the boss 30 into a circumferential groove 34 in said valve 29 blocks V endwise movement of the valve. The bore 35 of the valve 29 has an inner, radially ported end, as at 36, opening into one float chamber 6 and is partitioned transversely, as at 31, intermediate the discharge ports l4 so that its inner end opens into the other float chamber 6, but is closed off from the first mentioned float chamber. A pair of radial ports 38 are provided in said valve upon diametrically opposite sides thereof and upon opposite sides of the partition 37, said ports 38 being disposed to register with the discharge ports M, respectively, under an degree turn of the valve 29 in opposite directions. A pair of drain plugs 39 are threaded into the bottom 2 of the section I in the path of rotation of said ports 38 for draining the valve 29 of sediment.

The operation of my invention will be readily understood. The main section I is connected at its top, in theusual manner, to the intake manifold of the engine, not shown. By rotating the valve 29 in opposite directions through an arc of 180 degrees, either port 38 of said valve 29 may be registered with the related port [4 to establish communication between a selected float chamber 6 and the related main jet l5, together with the associated idling port I'I so that if one side of the carburetor fails the other side may be re sorted to. The manner in which the spray or 'vapor issuing from the main jets l5 and idling jets l'l mixes with the air in the mixing chamber 3 will be readily apparent and need not be entered into herein.

The foregoing will, it is believed, suflice to impart a clear understanding of my invention Without further explanation.

Manifestly the invention, as described, is susceptible of modification without departing from the inventive concept and right is herein reserved to such modifications as fall within the scope of the subjoined claim.

What I claim is:

In a dual carburetor, an upright main tubular section forming a mixing chamber and having a diametrically bored bottom, a pair of main jet members upstanding from said bottom at diametrically opposite sides thereof and opening-at the lower ends thereof into the top of said bore upon opposite sides of the transverse center of the latter, a pair of float chamber sections extending from opposite sides of said main section for connection to separate sources of similar fuel supply, respectively, and communicating with opposite ends of said bore, respectively, and a tubular valve member rotatably fitted in said bore and extending into both said float chamber sections in communication therewith, said valve member being partitioned transversely intermediate said jet members and provided with a pair of diametrically opposite radial ports therein upon opposite sides of said partition, respectively, whereby under rotation of said valve member through 180 of movement in opposite directions said ports may be registered with said jet members, respectively, to selectively connect said float chamber sections with said jet members, respectively, and means to rotate said valve member, the main section having a pair of ducts therein forming idling jets and extending downwardly through the wall of the section and across the bottom thereof and having lower ends communicating with the lower ends of said main jet members respectively.

EMMEI'I' K. CHAFFIN. 

